title: Association of pain with HbA1c in a predominantly black population of community-dwelling adults with diabetes: a cross-sectional analysis.
abstract: OBJECTIVE
  To assess the relationship between pain and HbA(1c) levels in a predominantly black population with diabetes, and to determine whether self-management behaviours (exercise and diet) and symptoms of depression mediate this relationship.
  
  
  METHODS
  We analysed cross-sectional data from 417 community-dwelling individuals with diabetes in rural Alabama, USA. Binary logistic regression was used to analyse the relationship between pain and HbA(1c) levels, defined as relatively good [≤ 64 mmol/mol (≤ 8.0%)] and relatively poor [> 64 mmol/mol (> 8.0%)], after adjusting for sociodemographics, insulin use, medication count, cigarette smoking history and body mass index (BMI). We examined the mediating roles of exercise, diet, and symptoms of depression using bootstrapping.
  
  
  RESULTS
  Participants were primarily black (86.6%), female (76.1%) and reported an annual income of ≤$20,000 (52.7%). Their mean (sd) age was 59.6 (12.8) years. The majority of the participants reported moderate to extreme pain (71.5%). Participants reporting pain were more than twice as likely to have HbA(1c) levels > 64 mmol/mol (8.0%) in the fully adjusted model (odds ratio 2.33 [95% CI 1.28-4.24]; P < 0.05). Diet significantly mediated the relationship between pain and HbA(1c) control (β = 0.06; 95% CI: 0.01-0.17), but only in the unadjusted model. Exercise and symptoms of depression were not significant mediators.
  
  
  CONCLUSIONS
  A significant independent relationship between pain and HbA(1c) control was found in this mainly black population, which was not explained by self-management behaviours or symptoms of depression. Future research is needed to delineate the mechanism by which pain influences HbA(1c) control, especially among black people with diabetes on low incomes.
authors.affiliation: Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Herbert
authors.forename: A L
authors.initials: AL
authors.lastname: Varley
authors.forename: S J
authors.initials: SJ
authors.lastname: Andreae
authors.forename: B R
authors.initials: BR
authors.lastname: Goodin
authors.forename: L A
authors.initials: LA
authors.lastname: Bradley
authors.forename: M M
authors.initials: MM
authors.lastname: Safford
mesh_terms: D001741:Black or African American / Q000706:statistics & numerical data*; D000407:Alabama / Q000453:epidemiology; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D059350:Chronic Pain / Q000097:blood* / Q000208:ethnology / Q000209:etiology; D003430:Cross-Sectional Studies; D003863:Depression / Q000208:ethnology / Q000209:etiology; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000150:complications / Q000208:ethnology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications / Q000208:ethnology; D003928:Diabetic Nephropathies / Q000097:blood; D004032:Diet; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D057187:Independent Living; D008297:Male; D008875:Middle Aged; D059352:Musculoskeletal Pain / Q000097:blood; D017288:Pain Threshold / Q000208:ethnology; D012424:Rural Population; D012648:Self Care; D012923:Social Class; D044465:White People / Q000706:statistics & numerical data*
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human